Am I the A hole

Me and my MIL had what I thought was a good relationship that is UNTIL I got pregnant. My husband has full custody of of his daughter and I love her like she is my own I even quit my job so I could stay home with her full time after we had got married in early April of this year. I take her to all her visitations with her mom.I’ve stepped up multiple times as the parent when neither of them could get along.before I got pregnant in in July his mom had always said shes so grateful how good I treat my step daughter and how i always step up and how I’ve made my husband a better dad. But ever since I’ve gotten pregnant she not only messages my husband and tells him how my step daughter needs to come live with her bc I’m not gonna treat her right now and I’m just gonna put our son first and not want to spend time with her but she has also told my my stepdaughter that as well SHE ONLY 3 years old and when she came back from spending the night my stepdaughter asked my why I don’t love her. When I have done nothing but preach about making sure she feels loved and not left out and we both need equally spend time with her when the baby gets here. His mom has done nothing but make me feel like crap about myself since we found out I was pregnant. I’m currently 24w 3 days and I told her that I will not be attending Christmas at her house bc I feel majorly disrespected and she told me I was being selfish and she has never done or said anything to hurt me and anytime I try to have a reasonable conversation she turns and plays the victim I have told her that our son is not to be around her and my husband full agrees and he called her out for being a narcissist and she thinks I’ve turned her son against her but that isn’t the case he can be around her all he wants and so can my step daughter I’m just not going to be neither is our son idk I’m just tired and needed to rant. I tried so hard to be nice and keep my mouth shut but I finally had enough. 😭